Looking closely at primary peritoneal cancer

The peritoneum is the lining of the pelvis and abdomen. When it becomes inflamed, for example after a ruptured appendix, the condition is called peritonitis.

The peritoneum is lined by the same type of epithelial cells that cover the ovaries and line the fallopian tubes.  Cancers of the ovary and fallopian tube commonly spread to the peritoneum, where they produce secondary deposits of cancer.

However, primary peritoneal cancers can also occasionally happen.  In these cases, the ovaries and tube are minimally involved, and the major spread is to the omentum, a fatty pad that hangs down from the stomach.  Most peritoneal cancers are serous carcinomas, which is also the most common type of ovarian cancer.

Women who have the breast-ovarian cancer syndrome, which is usually caused inheritance of the BRCA 1 or BRCA2 genetic mutation, are advised to have their children as early as possible and then have their tubes and ovaries removed, preferably before the age of 40 years. Unfortunately, about 1% of patients may still develop a primary peritoneal cancer.

Primary peritoneal cancer is usually quite advanced at the time of diagnosis, and often presents with abdominal swelling, due to excessive peritoneal fluid production, which is called ascites.  Other symptoms can include changes in bowel habits, a feeling of fullness after eating and vomiting or nausea.

Primary peritoneal cancer looks like ovarian or tubal cancer under the microscope and is staged and treated in the same way as these cancers.